Medical implants to replace or augment various parts of the mammalian body have been successfully used to reduce pain and improve function. For example, orthopaedic implants for replacing portions of bones and joints damaged by disease and/or trauma often eliminate pain and/or increase mobility. Orthopaedic implants for hips, knees, shoulders, ankles, elbows, wrists, the digits of the hands and feet, vertebral bodies, spinal discs, and other bones and joints have been developed. Many medical implants are made more versatile by providing them as separate modular components that can be combined to form an implant suited to a particular patient's condition. Where such modular components are supplied, a means for attaching them to one another is provided.
Increasingly, surgeons are turning to minimally invasive surgical techniques in which a surgical procedure is performed through small incisions to minimize trauma to surrounding tissues and speed patient recovery. One difficulty arising from the use of minimally invasive surgery with modular components is avoiding contamination of the junction between the components. In the process of inserting modular components through small incisions, body fluids and tissues are easily deposited on the junction surfaces. Such deposits may cause the junction to be less secure. Therefore, the surgeon often must carefully clean and dry the junction after inserting the components. This may be difficult or impossible depending on the shape and location of the junction and the size and orientation of the surgical incision. U.S. Pat. No. 6,863,692 issued Mar. 8, 2005, to the present inventor and addresses solutions to this problem. In the '692 patent a removable sleeve protects a modular junction of an implant and/or an anchoring portion of the implant. In one embodiment, a sleeve wipes a junction clean after insertion of implant components into a surgical site. In another embodiment, a sleeve covers a portion of an implant during insertion through the surgical wound and is then removed from the implant. In another embodiment, a sleeve covers a portion of an implant and is simultaneously withdrawn from the implant as the portion is seated in the surgical site such as into contact with a bone or into contact with cement.
Another difficulty arising from the use of minimally invasive surgery with modular components is aligning a second component with a previously inserted component so that they can be assembled. Minimally invasive incisions can be difficult to see into. Furthermore, such incisions can be deep and even convoluted. Therefore, upon insertion of a second component to be engaged with a previously inserted component, the surgeon may have to manipulate the joint position and/or the second component within the wound to get the components to engage. Such feeling around can prolong the surgical procedure, lead to contamination of the junction, and lead to poor alignment of the components.